/*
 * Simple I/O abstraction and context handling layer
 * Programmed and designed by Matti 'ccr' Hamalainen
 * (C) Copyright 2012-2020 Tecnic Software productions (TNSP)
 *
 * Please read file 'COPYING' for information on license and distribution.
 */
#include "th_ioctx.h"
#include <stdio.h>

#define CTX_FH ((FILE *) ctx->data)


static int th_stdio_fopen(th_ioctx *ctx)
{
    ctx->data = (void *) fopen(ctx->filename, ctx->mode);
    ctx->status = th_get_error();
    return (ctx->data != NULL) ? THERR_OK : THERR_FOPEN;
}


static void th_stdio_fclose(th_ioctx *ctx)
{
    if (CTX_FH != NULL)
    {
        fclose(CTX_FH);
        ctx->data = NULL;
    }
}


static int th_stdio_ferror(th_ioctx *ctx)
{
    return ctx->status;
}


static off_t th_stdio_ftell(th_ioctx *ctx)
{
    return ftello(CTX_FH);
}


static int th_stdio_fseek(th_ioctx *ctx, const off_t pos, const int whence)
{
    int ret = fseeko(CTX_FH, pos, whence);
    ctx->status = th_get_error();
    return ret;
}


static int th_stdio_freset(th_ioctx *ctx)
{
    return th_stdio_fseek(ctx, 0, SEEK_SET);
}


static off_t th_stdio_fsize(th_ioctx *ctx)
{
    off_t savePos, fileSize;

    // Check if the size is cached
    if (ctx->size != 0)
        return ctx->size;

    // Get file size
    if ((savePos = th_stdio_ftell(ctx)) < 0)
        return -1;

    if (th_stdio_fseek(ctx, 0, SEEK_END) != 0)
        return -1;

    if ((fileSize = th_stdio_ftell(ctx)) < 0)
        return -1;

    if (th_stdio_fseek(ctx, savePos, SEEK_SET) != 0)
        return -1;

    ctx->size = fileSize;
    return fileSize;
}


static BOOL th_stdio_feof(th_ioctx *ctx)
{
    return feof(CTX_FH);
}


static int th_stdio_fgetc(th_ioctx *ctx)
{
    int ret = fgetc(CTX_FH);
    ctx->status = th_get_error();
    return ret;
}


static int th_stdio_fputc(int v, th_ioctx *ctx)
{
    int ret = fputc(v, CTX_FH);
    ctx->status = th_get_error();
    return ret;
}


static size_t th_stdio_fread(void *ptr, size_t size, size_t nmemb, th_ioctx *ctx)
{
    size_t ret = fread(ptr, size, nmemb, CTX_FH);
    ctx->status = th_get_error();
    return ret;
}


static size_t th_stdio_fwrite(const void *ptr, size_t size, size_t nmemb, th_ioctx *ctx)
{
    size_t ret = fwrite(ptr, size, nmemb, CTX_FH);
    ctx->status = th_get_error();
    return ret;
}


static char * th_stdio_fgets(char *str, int size, th_ioctx *ctx)
{
    char *ret = fgets(str, size, CTX_FH);
    ctx->status = th_get_error();
    return ret;
}


static int th_stdio_fputs(const char *str, th_ioctx *ctx)
{
    int ret = fputs(str, CTX_FH);
    ctx->status = th_get_error();
    return ret;
}


static int th_stdio_vfprintf(th_ioctx *ctx, const char *fmt, va_list ap)
{
    int ret = vfprintf(CTX_FH, fmt, ap);
    ctx->status = th_get_error();
    return ret;
}


const th_ioctx_ops th_stdio_io_ops =
{
    "stdio",

    th_stdio_fopen,
    th_stdio_fclose,

    th_stdio_freset,
    th_stdio_ferror,
    th_stdio_fseek,
    th_stdio_fsize,
    th_stdio_ftell,
    th_stdio_feof,
    th_stdio_fgetc,
    th_stdio_fputc,
    th_stdio_fread,
    th_stdio_fwrite,

    th_stdio_fgets,
    th_stdio_fputs,
    th_stdio_vfprintf,
};